Mosquitos are well known as one of the less pleasant aspects of summer in Italy, but we’re now in mid-November and, in some areas at least, they’re still buzzing around.

This is unusual in itself, as Italy’s mosquito season is normally over by now. But this week experts warned that the nuisance insects could be with us for a few more weeks yet.

Without “a sudden and significant drop in temperatures” mosquitoes could stick around in some areas until Christmas, warned Alessandro Miani, the head of the Italian Society of Environmental Medicine (Società italiana di medicina ambientale, or Sima), in a report published by Italian media on Monday.

The agency’s latest report on the prevalence of mosquitos in Italy came as much of the country enjoyed late autumn sunshine this week, with temperatures around three degrees above average and highs of 23-24 degrees Celsius across the south.

While some sun in November isn’t unusual in Italy – in fact a short spell of sunny weather at this time of year is so common that it even has a name – the mosquito issue is due to a prolonged period of warm weather over the past few months, explained Miani.

“Temperatures well above seasonal averages have created favourable conditions for an alteration in the life and reproduction cycles of some insects,” he said.

“The anomalous heat allows mosquito eggs to survive and for adults to remain alive, reproduce and multiply.”

He noted that this “doesn’t only apply to types of mosquitoes that are more resistant to the cold, such as the Japanese or the Korean species, present especially in some areas of northern Italy, but also to the widespread common mosquito and the fearsome tiger mosquito.”

Italy has around 60 species of mosquito, he said, with more than 3,000 known species worldwide.

He pointed out that, as well as being annoying, being bitten by mosquitos in Italy brings some potentially serious health risks.

While serious diseases spread by mosquitos in Italy are relatively rare, they’re not completely unheard of: last year there was an outbreak of mosquito-borne West Nile virus in northern Italy, and in 2023 so far Italy’s national health institute (ISS) has recorded 306 cases of dengue fever, seven cases of Zika virus, and seven cases of chikungunya.